scholarly journals Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4

2016 ◽  
Vol 12 ◽  
pp. 636-642 ◽  
Author(s):  
Elena N Sigida ◽  
Yuliya P Fedonenko ◽  
Alexander S Shashkov ◽  
Nikolay P Arbatsky ◽  
Evelina L Zdorovenko ◽  
...  
Keyword(s):  
Soil Bacteria ◽  
Side Chain ◽  
Glucose Residue ◽  
Mild Acid Hydrolysis ◽  
Methyl Group ◽  
Specific Polysaccharide ◽  
Phenol Water ◽  
Hydrolysis Of ◽  
Mild Acid ◽  
C Nmr

An O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide isolated by the phenol–water extraction from the halotolerant soil bacteria Azospirillum halopraeferens type strain Au4. The polysaccharide was studied by sugar and methylation analyses, selective cleavages by Smith degradation and solvolysis with trifluoroacetic acid, one- and two-dimensional 1H and 13C NMR spectroscopy. The following masked repeating structure of the O-specific polysaccharide was established: →3)-α-L-Rhap2Me-(1→3)-[β-D-Glcp-(1→4)]-α-D-Fucp-(1→2)-β-D-Xylp-(1→, where non-stoichiometric substituents, an O-methyl group (~45%) and a side-chain glucose residue (~65%), are shown in italics.

scholarly journals Structure of the 4-O-[1-Carboxyethyl]-d-Mannose-Containing O-Specific Polysaccharide of a Halophilic Bacterium Salinivibrio sp. EG9S8QL

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 508
Author(s):  
Elena N. Sigida ◽  
Ibrahim M. Ibrahim ◽  
Maxim S. Kokoulin ◽  
Hussein H. Abulreesh ◽  
Khaled Elbanna ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr Spectroscopy ◽  
Halophilic Bacterium ◽  
Mild Acid Hydrolysis ◽  
1H And 13C Nmr ◽  
Specific Polysaccharide ◽  
Lake Qarun ◽  
Phenol Water ◽  
Hydrolysis Of ◽  
Mild Acid

The moderately halophilic strain Salinivibrio sp. EG9S8QL was isolated among 11 halophilic strains from saline mud (Emisal Salt Company, Lake Qarun, Fayoum, Egypt). The lipopolysaccharide was extracted from dried cells of Salinivibrio sp. EG9S8QL by the phenol–water procedure. The OPS was obtained by mild acid hydrolysis of the lipopolysaccharide and was studied by sugar analysis along with 1H and 13C NMR spectroscopy, including 1H,1H COSY, TOCSY, ROESY, 1H,13C HSQC, and HMBC experiments. The OPS was found to be composed of linear tetrasaccharide repeating units of the following structure: →2)-β-Manp4Lac-(1→3)-α-ManpNAc-(1→3)-β-Rhap-(1→4)-α-GlcpNAc-(1→, where Manp4Lac is 4-O-[1-carboxyethyl]mannose.

scholarly journals Studies of the polysaccharide fraction from the lipopolysaccharide of Pseudomonas alcaligenes

1974 ◽  
Vol 139 (3) ◽  
pp. 633-643 ◽  
Author(s):  
James A. Lomax ◽  
George W. Gray ◽  
Stephen G. Wilkinson
Keyword(s):  
Gel Filtration ◽  
Periodate Oxidation ◽  
Side Chain ◽  
Partial Hydrolysis ◽  
Methylation Analysis ◽  
Mild Acid Hydrolysis ◽  
Pseudomonas Alcaligenes ◽  
Crude Polysaccharide ◽  
Hydrolysis Of ◽  
Mild Acid

Studies of the lipopolysaccharide of Pseudomonas alcaligenes strain BR 1/2 were extended to the polysaccharide moiety. The crude polysaccharide, obtained by mild acid hydrolysis of the lipopolysaccharide, was fractionated by gel filtration. The major fraction was the phosphorylated polysaccharide, for which the approximate proportions of residues were; glucose (2), rhamnose (0.7), heptose (2–3), galactosamine (1), alanine (1), 3-deoxy-2-octulonic acid (1), phosphorus (5–6). The heptose was l-glycero-d-manno-heptose. The minor fractions from gel filtration contained free 3-deoxy-2-octulonic acid, Pi and PPi. The purified polysaccharide was studied by periodate oxidation, methylation analysis, partial hydrolysis, and dephosphorylation. All the rhamnose and part of the glucose and heptose occur as non-reducing terminal residues. Other glucose residues are 3-substituted, and most heptose residues are esterified with condensed phosphate residues, possibly in the C-4 position. Free heptose and a heptosylglucose were isolated from a partial hydrolysate of the polysaccharide. The location of galactosamine in the polysaccharide was not established, but either the C-3 or C-4 position appears to be substituted and a linkage to alanine was indicated. In its composition, the polysaccharide from Ps. alcaligenes resembles core polysaccharides from other pseudomonads: no possible side-chain polysaccharide was detected.

Sequential Enzymatic and Mild-Acid Hydrolysis of By-Product of Carrageenan Process from Kappaphycus alvarezii

2019 ◽  
Vol 12 (2) ◽  
pp. 419-432 ◽  
Author(s):  
Fernando Roberto Paz-Cedeno ◽  
Eddyn Gabriel Solórzano-Chávez ◽  
Levi Ezequiel de Oliveira ◽  
Valéria Cress Gelli ◽  
Rubens Monti ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Kappaphycus Alvarezii ◽  
Mild Acid Hydrolysis ◽  
Hydrolysis Of ◽  
Mild Acid

scholarly journals IMMUNOCHEMICAL STUDIES ON BLOOD GROUPS

1971 ◽  
Vol 133 (1) ◽  
pp. 39-52 ◽  
Author(s):  
Ten Feizi ◽  
Elvin A. Kabat ◽  
Giuseppe Vicari ◽  
Byron Anderson ◽  
W. Laurence Marsh
Keyword(s):  
Acid Hydrolysis ◽  
Blood Group ◽  
Ovarian Cyst ◽  
Periodate Oxidation ◽  
Human Saliva ◽  
Mild Acid Hydrolysis ◽  
Group B ◽  
Hydrolysis Of ◽  
Substantial Heterogeneity ◽  
Mild Acid

A partially purified blood group-like substance obtained from milk showed I activity with 2 of 21 anti-I sera. With these antisera, certain human ovarian cyst substances considered to be precursors of the A, B, H, Lea, and Leb substances also showed I activity comparable to the milk material. Strong I activity could be produced by one-stage periodate oxidation and Smith degradation of human ovarian cyst A and B substances, or of hog mucin A + H substance, or by mild acid hydrolysis of human saliva or ovarian cyst blood group B substance. The two sera indicate that I specificity appears at intermediate stages in the biosynthesis of the A, B, H, Lea, and Lea substances. Anti-I sera differ strikingly in their specificities, indicating substantial heterogeneity of the I determinants.

The Synthesis of Trisubstituted Enol Ethers and of Methyl Ketones from Ketones

1973 ◽  
Vol 51 (6) ◽  
pp. 981-983 ◽  
Author(s):  
Gilles Caron ◽  
Jean Lessard
Keyword(s):  
Acid Hydrolysis ◽  
Hydroxy Acid ◽  
Reliable Method ◽  
Acid Salt ◽  
Methyl Ketones ◽  
Enol Ether ◽  
Mild Acid Hydrolysis ◽  
Enol Ethers ◽  
Hydrolysis Of ◽  
Mild Acid

A reliable method for the synthesis of trisubstituted enol ethers (and of the corresponding methyl ketones) is described involving the condensation of the α-lithiated 2-methoxypropionic acid salt with a ketone to give a β-hydroxy acid, the cyclization to a β-lactone which is then decarboxylated (and mild acid hydrolysis of the enol ether).

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